This invention relates to plug-in terminal current control devices, and while some aspects thereof deal with such control devices generally, it has its most important application in flasher devices used, for example, in automobiles to interrupt the flow of current to the tail lights thereof to provide a warning light indication.
Flasher devices of the type described being an important safety device in an automobile must be made with a high degree of reliability. Also, the cost of such devices becomes an important objective to the manufacturer. Reliability and low cost are generally difficult to achieve simultaneously.
A flasher device of the type described generally includes a support base having a pair of plug-in terminals extending therefrom and a movable contact carrying arcuately bent blade electrically connected to one of the terminals. The other terminal of the device is commonly provided with a conductive extension carrying a stationary contact in confronting relationship to the movable contact of the heat responsive blade. The heat responsive blade commonly includes an actuator ribbon extending therefrom and a heater coil wound on the actuator ribbon is electrically connected between the heat responsive blade and the terminal extension. The actuator ribbon is heated initially by current flow in the heater coil until the ribbon reaches a temperature where it expands to a point permitting the blade to snap into a contact closing position to short circuit current flow through the heating coil. The actuator ribbon will thus be alternately heated and cooled to effect opening and closing of the movable and stationary contacts alternately to energize and de-energize the electrical circuit into which the flasher device is placed.
The assembly of such a flasher device generally requires a number of welding or soldering operations electrically to connect the various parts of the device to one another and to the one or more terminals thereof. It has been heretofore recognized that the reliability of a flasher device progressively decreases as the number of solder or welding points in the path of the current flow and the number of parts of the device increases. Also, since the ability of a flasher device properly to operate depends, in part, upon the maintenance of a pre-determined positioning between the movable and stationary contacts, it becomes important to design the flasher device so vibration and other forces applied to it do not disturb this proper positioning of the stationary and movable contacts. It is, therefore, one of the objects of the invention to provide a flasher device as described wherein the number of solder or welding points thereof are reduced to increase the reliability thereof. A related object of the invention is to provide a flasher device as described which is made of fewer parts than prior flasher devices. A still further object of the invention is to provide a flasher device as described wherein vibration and other forces applied thereto do not disturb the proper relative positioning of the movable and stationary contacts. An overall object of the invention is to provide a flasher device having one or more of the advantageous features just described, and further which can be easily and economically assembled.